Cisco Wireless Residential Gateway Remote Code Execution flaw

By paganinip on July 17th, 2014

Multiple Cisco Wireless Residential Gateway products are affected by a critical flaw that could allow a remote attacker to hijack the devices.

A security vulnerability affects multiple Cisco wireless residential Gateway products, the flaw resides on the web server an could be exploited by a remote attacker to hijack the network appliance. The flaw, ranked with CVSS Base Score - 10.0, is very serious because the diffusion of the Cisco network devices and due to the possibility to exploit remotely the flaw.

Several Cisco cable modems and wireless residential gateways are plagued by a vulnerability that can be exploited for remote code execution, the company said on Wednesday.

According to Cisco, a buffer overflow flaw affecting the Web server embedded into the devices can be leveraged by a remote, unauthenticated attacker to inject arbitrary commands and execute arbitrary code with elevated privileges.

The vulnerability, which exists regardless if the device is configured in Gateway or Router mode, was reported to Cisco by Chris Watts of Tech Analysis, and has been assigned the CVE identifier CVE-2014-3306. The company said that it is not aware of any attacks in the wild which this flaw has been leveraged.

"The vulnerability is due to incorrect input validation for HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. Successful exploitation could allow the attacker to crash the web server and execute arbitrary code with elevated privileges," Cisco explained in its advisory .

Re: Cisco Wireless Residential Gateway Remote Code Execution flaw

Cisco has shipped a patch for a buggy Open Shortest Path First (OSPF) routing implementation it says offers exploits that include traffic blackholing or interception.

As the advisory notes, the vulnerability “could allow an unauthenticated attacker to take full control of the OSPF Autonomous System (AS) domain routing table, blackhole traffic, and intercept traffic”, which makes El Reg wonder why the NSA ever had to go to the alleged bother of intercepting hardware for to allegedly install its compromises.

Crafted OSPF packets can be sent to devices running the faulty code, and those packets would make the targeted router flush its routing table. A crafted OSPF Link State Advertisement (LSA) type 1 update can then be propagated through a targeted domain.